Comment 1 for bug 1922482

I suspect the preview isn't updating until the changes are "committed" (e.g. changing focus to another widget in the dialog), but I haven't been able to reproduce the issue with the updated blur value being ignored after pressing Ok. I'm testing on macOS, though

Would you be able to see if this also occurs for you on the GTK3 builds? (https://github.com/PintaProject/Pinta/tree/gtk3-v2 or pre-built from https://github.com/PintaProject/Pinta/actions?query=branch%3Agtk3-v2)